* You will not be able to play games you previously used to - try planeshift instead of WoW, it's better because it's opensource, you can contribute code to the project. And your documents when opened with OOo won't look or be 100% compat. with MS Office. Also your chat programme won't support all the features your current one does, but who needs to be able send stupid sound samples and huge smilies like Yahoo messenger does? The devs didn't code anything like that because you actually need friends for that... which they don't have being geeks and all.

* You will not be able to play games you previously used to - try planeshift instead of WoW, it's better because it's opensource, you can contribute code to the project. And your documents when opened with OOo won't look or be 100% compat. with MS Office. Also your chat programme won't support all the features your current one does, but who needs to be able send stupid sound samples and huge smilies like Yahoo messenger does? The devs didn't code anything like that because you actually need friends for that... which they don't have being geeks and all.

a. The gaming argument is lame. There are plenty of games for GNU/Linux and most games are not played on a PC anymore as you may have noticed. WOW works fine on GNU/Linux I hear.
b. If there are problems with Microsoft docs that is entirely up to Microsoft, compatibility & open standards it is called !
c. There are so many chat programs for GNU/Linux, that there must be one that comes close to or has the specific functions a particular user wants/needs. Try aMSN or Skype or Pidgin or Kopete etc. for just chat with all your email buddies use Google-chat !
d. But the most important point is that is is 'free'&'free', free as in freedom but also free as in 'gratis'.
Now can Microsoft beat that ?

One of the key reasons you need your little disclaimer there about things like games platform support, document compatibility with MS Office, and interoperability with IM networks like MSN chat, is that MS are in a monopoly position and have been abusing their monopoly position to protect their marketshare.

That warning about Office documents should also be shown each time you buy new version of Office - their backward compatibility is worse than OOs in my experience. Well, OOo 2.4-3.0 migration gets close to Microsoft standards here, as it's pretty painful too.